1. Field of the Invention
The present invention relates to communication networks and, more particularly, to a method and apparatus for discovering, negotiating, and provisioning, End-to-End SLAs between multiple service provider domains.
2. Description of the Related Art
Data communication networks may include various computers, servers, nodes, routers, switches, bridges, hubs, proxies, and other network devices coupled to and configured to pass data to one another. These devices will be referred to herein as “network elements.” Data is communicated through the data communication network by passing protocol data units, such as Internet Protocol (IP) packets, Ethernet frames, data cells, segments, or other logical associations of bits/bytes of data, between the network elements by utilizing one or more communication links between the devices. A particular protocol data unit may be handled by multiple network elements and cross multiple communication links as it travels between its source and its destination over the network.
A large network may be managed by multiple administrative domains, which may be owned by the same entity or owned by different entities. The domains may be interconnected to enable customers on one domain to exchange data with customers on another domain or with servers that are connected to another domain. Large numbers of domains may be interconnected in this manner, such that a given path across the network may span multiple domains which possibly may be owned by many different entities.
A service provider may have contracts with customers to provide access to the network and to implement services for the customers on the network. The Service provider may provide any type of network service, such as access, metro or core. An agreement that specifies the type of network access and network services to be provided is commonly referred to as a Service Level Agreement (SLA). The SLA may specify many aspects of the service that is to be provided to the customer on the network. For example, the SLA may specify the QoS to be provided to the customer in terms of committed Bandwidth, Delay, Jitter and Packet Loss Ratio, the availability of the network, the security to be provided for the service, and also whether the service is provided is in the form of a Virtual Private Network (VPN) service with the above mentioned guarantees.
When the service provider enters into an SLA with a customer for a service that is required to traverse multiple domains implemented and provided by multiple third parties, the provider may want to learn the guarantees in terms of QoS, availability and what security guarantees, may be expected from the networks owned by those third parties. Thus, the service provider may wish to know what service offerings are available from the other domains before entering into a SLA with a customer to provide a particular set of services.
Additionally, a service provider may be able to provide the same service using multiple different network providers by selecting different paths through multiple providers to cause the service to traverse different intermediate domains. Thus, a service provider may wish to learn the type of service assurances that intermediate domains can provide and the costs of those services, and then select a set of network providers that are able to provide network connectivity that will allow the access provider to satisfy the SLA that it has entered with its customer. In this instance, a provider would like to obtain SLA information from third party service providers and then select one or more network service providers that may provide the connectivity for the customer, while striking a balance between various service constraints such as service realization Cost, QoS, Availability and Security requirements.
With respect to service provisioning, service providers have typically followed a ‘walled garden’ approach, in which the internal properties of a network are available to an access provider only through closed door contact and negotiations. Such a setup is usually unproductive and does not enable a dynamic service creation paradigm. Unfortunately, the type of service assurance information desired by access providers is not available where service providers are operating in a walled garden approach. Thus, a provider may not have information about the types of services that may be available end-to-end through the network when entering into the service level agreement with the customer. Particularly where the provider would like to set up a service dynamically, the provider may not know the state of the other provider networks to negotiate SLAs for service assurances and provision services on demand. For example, the customers on a provider network may want to subscribe to a live event and be provided with particular guarantees as to available bandwidth, delay, jitter, etc., before agreeing to pay for access to the live event. Since the provider doesn't have access to this information about the capabilities of the intermediate network domains, the provider may not know what type of services may be available on the network as a whole. Accordingly, it would be advantageous to provide a method and apparatus for exchanging SLA information between network domains.